On Wednesday night, in front of a packed house in Portland, Oregon, and a television audience around the globe, Landon Donovan netted the game-winning goal to lead MLS All-Stars over one of his former clubs, Bayern Munich.

One day later, Donovan officially announced his retirement from professional soccer, effective at the end of this MLS season.

It's a heck of a way to go out.

Donovan officially announced his retirement on his Facebook page Thursday afternoon. In part:

After careful deliberation and after many conversations with those closest to me, I have decided that this will be my last season as a professional soccer player.

I don't write these words lightly and this day carries mixed emotions for me. I am sad to leave a profession that has brought me so much joy. ...

... I feel incredibly blessed and lucky to have played a role in the remarkable growth of MLS and US Soccer during my playing career. And while my career as a player will soon be over, rest assured I will stay connected on many levels to the beautiful game.

It's hard to put into words exactly what Donovan has meant to soccer in this country. He is without question the best American man ever to wear the red, white and blue on a soccer field, and his play for the U.S. national team helped usher in a new generation of talent that, ironically, made his inclusion in this year's World Cup unnecessary.

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Still, even without the trip to Brazil, Donovan's legacy as a U.S. international is unparalleled. In 1999 he won the Golden Ball at the U-17 World Cup. Three years later he was named to the All World-Cup team in 2002, and eight years after that he scored one of the most memorable goals in United States soccer history, with a host of enormously impactful moments in between.

Donovan played in more than 150 games for the USMNT and has a record 57 goals in his insanely productive career. He holds the record for most assists for a U.S. player as well, also with 57, and has the most points—171 in total—of any American man in the team's history.

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Let's not forget Donovan is the leading goalscorer in MLS history as well, with 138, breaking that record while his U.S. teammates were preparing to embark on their World Cup journey without him this summer.

Donovan is also second in league history in assists, with 124, 11 shy of breaking that record, just within reach with 15 more regular-season games to go for LA Galaxy.

Whether he breaks that record or not, there is little debate that Donovan is one of the best players—if not the absolute best—in MLS history.

And yet none of that even begins to tell the story of how important Donovan has been to American soccer over the last 15 years.

This is a really hard thing to do; to put a man's career into perspective when he has meant this much to more than just a team, or a league, but a sport's entire culture in this country.

It says something about the state of U.S. soccer that Donovan is widely regarded as the best player in our history yet was never looked at as a truly world-class player in his prime.

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His stints in the Bundesliga—with Bayer Leverkusen, then on a short loan with Bayern—were ill-fated, and while he was an important piece of multiple teams while on loan at Everton, he never had an impact on European football the way the best American player should.

In a way, for Donovan, that's almost a compliment.

He was unnecessarily loyal to MLS during his career. Two years ago when the writing was on the wall that his career was nearing its end—before the sabbatical last year that looked like the end of his time with both the U.S. national team andMLS—there was talk of Donovan going back to Everton again, to give it one more shot to really test his abilities against some of the best competition in the world.

Instead, Donovan stayed with the Galaxy and won another championship in America. That title may not have meant much around the world—a Europa League spot for an EPL club probably carries more international weight than MLS Cup in America—but it was important for Donovan's team, for his city and for American domestic soccer.

Our best player was playing at home.

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Over the last few years, it's clear Donovan wasn't our best player anymore. First Clint Dempsey seemed to pass him in status among USMNT faithful. Recently it's been Michael Bradley who has held the mantle of America's best. Both of those players—along with a host of USMNT talent—are back in MLS.

A lot of that has to do with Donovan.

It goes beyond just the U.S. soccer players, too. It's hard to know if David Beckham would ever have landed in Los Angeles were it not for the cachet Donovan added to that club and the league at a time when most around the world did not have a very good opinion of MLS.

Beckham is credited (rightly so in my mind) with ushering a new culture in MLS, where coming to America is not a cause for derision around the world but celebration of a budding, strong league. But there may have been no Beckham without someone like Donovan.

Even when Beckham was the one grabbing all the front-page photo ops, it was Donovan—never one to hold his opinions to himself—who called out the global icon in defense of MLS. This, from July 2009 in The Guardian via Grant Wahl's bookThe Beckham Experiment:

Does the fact that he earns that much money come into it? Yeah. If someone's paying you more than anybody in the league, more than double anybody in the league, the least we expect is that you show up to every game, whether you're suspended or not.

Show up and train hard. Show up and play hard. Maybe he's not a leader, maybe he's not a captain. Fair enough. But at a minimum you should bust your ass every day. That hasn't happened. And I don't think that's too much for us to expect. Especially when he's brought all this on us.

I can't even say he's a good teammate any more.

Later that year, the Galaxy made it to MLS Cup. Two years later (and the year after that), they won the title.

MLS as an organization has never been stronger than it is today. A lot of that is due to the commitment of players and ambassadors like Donovan who would routinely defend the league to anyone, including some of its own star players.

Mark J. Terrill/Associated Press

Besides, the guy just doesn't give a crap what anyone thinks of him and has never backed down from expressing his opinion, especially about his (and our) place in the game. Donovan has earned that right over the years, and he has earned the respect of every person who has ever laced up a pair of boots on American soil.

And with that, Donovan's legacy is secure, and his place in the annals of American soccer will never be forgotten. He, perhaps more than anyone in the league's history, truly helped legitimize both MLS and American soccer around the world. The league will keep growing, and talent from around the globe will continue to populate its ranks, thanks to players like Donovan.

In 15 years, will we still remember Donovan as the best American field player of all time? Will we think that in five years?

If U.S. soccer wants to grow, we better hope not, but in finding a new crop of talent, even more respect and appreciation will have to go to someone like Donovan.

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How many kids now look at MLS as a viable path to the U.S. national team because of him? How many players in parks around the country have grown up hoping to be the next Landon Donovan? How many of them will end up being even better?

There's no stat sheet that can measure that impact. There's no amount of awards or trophies that can express how important he has been. It's a different world in American soccer after this. Thanks to Donovan, it's a better world too.